WeeklySA_AdminADVERSE: New research suggests users of the weight-loss drug Wegovy may face a significantly higher risk of a rare eye condition that can cause sudden vision loss, although experts say more studies are needed to confirm a direct cause…
By Corrie Pelc
As the use of GLP-1 medications for weight loss expands globally, researchers are increasingly examining their potential effects beyond metabolic health — including their impact on eye health.
A new study published in the British Journal of Ophthalmology suggests that people using the weight-loss drug Wegovy may face a higher risk of developing ischemic optic neuropathy (ION), a condition that can lead to sudden vision loss.
ION is an umbrella term for disorders affecting blood flow to the optic nerve, including non-arteritic anterior ischemic optic neuropathy (NAION), a rare but serious eye condition.
Researchers analysed data from the United States Food and Drug Administration’s Adverse Event Reporting System (FAERS) covering the period between December 2017 and December 2024.
The study focused on reports linked to semaglutide, the active ingredient in several widely used GLP-1 medications:
• Ozempic – weekly injection for type 2 diabetes (up to 2 mg);
• Rybelsus – daily oral tablet for type 2 diabetes;
• Wegovy – weekly injection for obesity (up to 2.4 mg).
Among more than 30 million adverse event reports in the database, about 32 000 were linked to semaglutide medications, with users averaging 56 years of age and 54% female.
Approximately 3 000 reports involved Wegovy, while around 21 000 were linked to Ozempic, coming from countries across several continents.
Wegovy versus Ozempic
Despite the larger number of reports associated with Ozempic, researchers found that Wegovy was more strongly associated with cases of ischemic optic neuropathy.
The study estimates that:
• The odds of developing ION were about five times higher for Wegovy users than for Ozempic users.
• The risk appeared more than three times higher in men than in women.
• No ION cases were reported in association with Rybelsus in the dataset.
Although Wegovy and Ozempic contain the same active ingredient, semaglutide, the dosage used in Wegovy is higher.
Dr Benjamin Bert, a board-certified ophthalmologist at MemorialCare Orange Coast Medical Center in California who was not involved in the study, said the difference may point to a dose-related risk.
“It was surprising to see the increase in risk of NAION with Wegovy compared to other GLP-1 medications, particularly Ozempic, since they share the same active ingredient,” Bert said.
Wegovy can deliver up to 2.4 mg of semaglutide, compared with up to 2.0 mg for Ozempic, which researchers believe could help explain the difference.
“The difference in dosage and the rates of NAION may indicate a dose-dependent increase in risk,” Bert added.
Experts urge caution
However, experts stress that the findings show an association rather than proof of cause.
Dr Dimitra Skondra, vice chair of research in ophthalmology at NYU Grossman School of Medicine, said people who use GLP-1 medications often already have conditions that increase their risk of eye disease. These include: diabetes, obesity, cardiovascular disease and vascular health problems.
“Patients who require GLP-1 medications often have underlying vascular and metabolic risk factors which themselves increase the risk of ischemic optic neuropathy,” Skondra explained.
She emphasised that further research is needed to determine whether the medications themselves play a direct role.
More research needed
GLP-1 drugs such as Wegovy and Ozempic are used by millions of patients worldwide, largely because they have shown major benefits in controlling blood sugar, promoting weight loss and reducing cardiovascular risk.
Researchers say the latest findings highlight the need for carefully designed clinical studies to determine whether semaglutide may affect blood flow to the optic nerve or whether the observed association reflects underlying health risks among patients.
“We should take this signal seriously,” Skondra said, “but more controlled prospective studies are needed to determine whether there is a true causal relationship.”. – NMT
